pythongh-139495: Fix hashlib.file_digest() versionchanged description of BlockingIOError (pythonGH-139496)

* Fix `hashlib.file_digest()` versionchanged description of `BlockingIOError`

The sentence was missing a negation and contradicted the other two
descriptions in the same commit. I believe code behaviour is correct.

* fixup! Fix `hashlib.file_digest()` versionchanged description of `BlockingIOError`

* Remove unncessary NEWS.d entry
(cherry picked from commit fb114cf)

Co-authored-by: Alex Willmer <alex@moreati.org.uk>

Author: moreati

Doc/library/hashlib.rst

@@ -303,7 +303,7 @@ a file or file-like object.
    .. versionadded:: 3.11
 
    .. versionchanged:: 3.14
-      Now raises a :exc:`BlockingIOError` if the file is opened in blocking
+      Now raises a :exc:`BlockingIOError` if the file is opened in non-blocking
       mode. Previously, spurious null bytes were added to the digest.